Evaluation of late pregnancy bleeding

* Hemodynamic instability and fetal heart rate abnormalities may represent obstetric emergencies that both influence the likely diagnosis and require modification of the evaluation.
¶ In women with uterine bleeding and a previous cesarean delivery or transmyometrial surgery, the possibility of uterine rupture should always be considered. Uterine rupture is most likely to occur during labor or as a result of abdominal trauma but may occur spontaneously. Abdominal pain, fetal heart rate abnormalities, and maternal hemodynamic instability due to intraabdominal bleeding are likely but not always present.
Δ Women with bleeding and contractions in the second trimester but less than 20 weeks of gestation are diagnosed with threatened miscarriage rather than labor. Ectopic pregnancy is rare at this gestational age; the location is generally nontubal (eg, corneal or abdominal) and may be detected by careful ultrasound examination.
◊ "Bloody show" is the term used to describe the small amount of blood with mucus discharge that may precede the onset of labor by as much as 72 hours. The presumptive diagnosis of bleeding in excess of bloody show is abruptio placentae, which may or may not be associated with labor. Refer to UpToDate topics on abruptio placentae.
§ If there is no visible blood on speculum examination, consider rectal bleeding (such as hemorrhoids) as the possible source of bleeding.